The present invention generally relates to refrigeration systems. This invention relates more particularly to a refrigeration system using a single refrigerant of R32 or a mixture of refrigerants containing R32.
Refrigerant R22, which is suitable for use as a refrigerant in refrigeration systems (e.g., air conditioning apparatus), has been used in many cases. However, R22, because of its high ozone depletion potential (ODP), is scheduled for total abolition by the year of 2020 according to the Montreal Protocol. Therefore, the development of various refrigerants as a replacement for R22 such as refrigerants R407C, R410A, and R134a is now proceeding.
As shown in FIG. 10, although these replacement refrigerants are low ODP refrigerants, their global warming potential (GWP) is similar to that of R22. Therefore, from the viewpoint of global warming prevention, the aforesaid replacement refrigerants are hardly acceptable.
Further, the use of these replacement refrigerants causes a refrigeration system to fall lower in COP (coefficient of performance) in comparison with currently-used conventional refrigerants. With the increase in power consumption the load of, for example, thermal power generation plants increases. This, apart from direct global warming due to refrigerant release, results in indirectly furthering global warming. There has been strong desires for the development of replacement refrigerants capable of truly contributing to the suppression of global warming.
Accordingly, the development of a single refrigerant of R32 or a mixture of refrigerants containing R32 in a great amount as a replacement refrigerant of low GWP is now proceeding.
However, that an existing refrigeration system designed for R22 is simply charged with a single refrigerant of R32 or with a mixture of refrigerants containing R32 will not take full advantage of the characteristics of R32, and it is impossible to sufficiently achieve global warming prevention. There have been strong demands for refrigeration systems capable of making good utilization of the characteristics of R32 for the purpose of global warming prevention.
Bearing in mind the above problems, the present invention was made. Accordingly, an object of the present invention is to provide a refrigeration system capable of making good utilization of the characteristics of R32 and of truly contributing to global warming prevention.
In order to achieve the above object, the present invention provides such arrangement that the diameter of a gas side pipe of a refrigerant circuit remains the same as a conventional gas side pipe whereas the diameter of a liquid side pipe is set smaller than that of a conventional liquid side pipe, whereby the refrigerant charging amount of the refrigerant circuit is reduced while maintaining the system performance at the same level as conventional technology.
More specifically, a first invention of the present application is intended for a refrigeration system comprising a refrigerant circuit (10) forming a refrigerating cycle. In the refrigeration system, a dg/dl ratio, which is the ratio of the diameter dg of a gas side pipe (31) of the refrigerant circuit (10) to the diameter dl of a liquid side pipe (32) of the refrigerant circuit (10), is not less than 2.6.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32 and which comprises a refrigerant circuit (10) forming a refrigerating cycle. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), is not less than 2.6.
By the xe2x80x9cdiameterxe2x80x9d is meant an inside or outside diameter in each of the above-described inventions.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of more than 5 kW but not more than 9 kW. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), is not less than 2.1.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of more than 5 kW but not more than 9 kW. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), falls in the range of 2.1 to 3.5.
Furthermore, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of more than 5 kW but not more than 9 kW. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), falls in the range of 2.4 to 3.2.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of more than 5 kW but not more than 9 kW. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), falls in the range of 2.6 to 3.0.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not more than 5 kW or more than 9 kW. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), is not less than 2.6.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not more than 5 kW or more than 9 kW. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), falls in the range of 2.6 to 3.5.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not more than 5 kW or more than 9 kW. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), falls in the range of 2.8 to 3.3.
Furthermore, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not more than 5 kW or more than 9 kW. In the refrigeration system, a liquid side pipe (32) and a gas side pipe (31) of the refrigerant circuit (10) are formed such that a dg/dl ratio, which is the ratio of the diameter dg of the gas side pipe (31) to the diameter dl of the liquid side pipe (32), falls in the range of 2.9 to 3.1.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not more than 5 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which is not more than 4.2 mm.
Furthermore, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not more than 5 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 3.2 mm to 4.2 mm.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not more than 5 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 3.5 mm to 3.9 mm.
Furthermore, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not more than 5 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 3.6 mm to 3.8 mm.
The inside diameter of the liquid side pipe (32) is preferably no more than 3.7 mm from the viewpoint of reducing the charging amount of refrigerant to a grater extent than conventional cases.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of more than 5 kW but less than 22.4 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which is not more than 7.0 mm.
Furthermore, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of more than 5 kW but less than 22.4 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 5.4 mm to 7.0 mm.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of more than 5 kW but less than 22.4 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 5.7 mm to 6.7 mm.
Furthermore, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of more than 5 kW but less than 22.4 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 6.0 mm to 6.4 mm.
The inside diameter of the liquid side pipe (32) is preferably no more than 6.2 mm from the viewpoint of reducing the charging amount of refrigerant to a greater extent than conventional cases.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not less than 22.4 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which is not more than 9.8 mm.
Furthermore, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not less than 22.4 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 7.5 mm to 9.8 mm.
Further, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not less than 22.4 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 7.8 mm to 9.5 mm.
Furthermore, another invention of the present application is intended for a refrigeration system which uses, as its refrigerant, either a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 or a single refrigerant of R32, which comprises a refrigerant circuit (10) forming a refrigerating cycle, and which has a cooling rated capacity of not less than 22.4 kW. In the refrigeration system, a liquid side pipe (32) of the refrigerant circuit (10) is formed by a pipe the inside diameter of which falls in the range of 8.1 mm to 9.1 mm.
The inside diameter of the liquid side pipe (32) is preferably no more than 8.7 mm from the viewpoint of reducing the charging amount of refrigerant to a greater extent than conventional cases.
In each of the above-described inventions, the inside diameter of the liquid side pipe (32) of the refrigerant circuit (10) is set smaller than that of conventional liquid side pipes. Further, R32 single refrigerant or a mixture of not less than 75 wt. % but less than 100 wt. % R32 and R125 exhibits, as its refrigerant characteristic, less pressure loss than R22. Therefore even when the inside diameter of the liquid side pipe (32) is lessened, the tube pressure loss is maintained at the same level as conventional cases.
On the other hand, as the inside diameter of the liquid side pipe (32) is lessened, the refrigerant charging amount of the refrigerant circuit (10) is reduced. While maintaining the same performance that conventional R22 achieves, the charging amount of refrigerant is reduced. In addition to the fact that R32 has a low GWP, the refrigerant charging amount of the refrigerant circuit (10) is reduced. This considerably contributes to global warming effect reduction.
In each of the foregoing inventions, the liquid side pipe (32) may be the entirety of a pipe between the condenser outlet and the evaporator inlet or may be a part thereof. Likewise, the gas side pipe (31) may be the entirety of a pipe between the evaporator outlet and the condenser inlet, may be the entirety of a pipe between the evaporator outlet and the compressor suction side, or may be a part thereof.
The gas side pipe (31) and the liquid side pipe (32) may be connecting pipes for connecting an indoor unit (17) and an outdoor unit (16).
The liquid side pipe (32) may be a liquid side connecting pipe for connecting the indoor unit (17) and the outdoor unit (16).
In the above inventions, the length of connecting pipes is likely to be long, so that the refrigerant charging amount reduction effect is achieved more significantly.
Further, it is preferable that the refrigerant be an R32 single refrigerant.
As described above, in accordance with the present invention, the inside diameter of the liquid side pipe (32) is made smaller than conventional systems using R22. This makes it possible to reduce the refrigerant charging amount of the refrigerant circuit (10) while maintaining the performance at the same level as that of conventional systems. Accordingly, it becomes possible to make better use of an R32 single refrigerant or a mixture of refrigerants containing R32 in comparison with conventional cases. The reduction in GWP of refrigerant itself and the reduction in refrigerant charging amount considerably reduce the effect of global warming. Accordingly, systems suitable for preservation of the global environment.